Speaking after the ceremony, Mr George said: "Although we acknowledge that there are few speakers of the language, there is symbolism in using a tongue which has been widely spoken during the lifetime of our Parliamentary democracy.

"It is right that we should both recognise and celebrate the diversity of cultures, languages and histories of the country in the Houses of Parliament.

"This small but significant action helps to put Cornwall on the map for the right reasons."

All MPs are obliged to first swear the oath - or affirm their allegiance - in English but some choose to repeat it in Welsh or Gaelic as well.

Labour's Ann Clwyd (Cynon Valley) and Liberal Democrat Lembit Opik (Montgomeryshire) were among those who proclaimed their loyalty in Welsh.